The proposed research includes studies of (1) the microsurgical anatomy of the central nervous system of man, (2) the sensory components of cranial nerves V, IX and X and (3) the innervation of the arteries of the brain. (1) Microsurgical anatomy of the central nervous system of man: The rapid growth of the field of microneurosurgery (clinical neurosurgery done using magnification) has created a need for detailed studies of normal microsurgical anatomy. The areas to be studied in autopsy specimens include the jugular foramen, sellar region, ventricular system and cavernous sinus. Studies of the internal acoustic meatus and temporal bone are to be continued. (2) The sensory components of cranial nerves V, IX, and X: A Nauta- Gygax and Fink-Heimer degeneration study of central connections of cranial nerves V, IX and X in the rat, cat and monkey is to be completed. A degeneration study of the central connections of the sensory fibers in the motor root of the trigeminal nerve is to be done. (3) Innervation of the arteries of the brain: Studies of the normal pattern of innervation of intracranial arteries as seen in whole mounts stained by silver technic are to be completed. Degeneration studies to define contributions of cranial nerves VII, IX and X and the upper cervical roots to the cerebral arterial nerve bundles will be done. In addition, the normal course of the larger nerve bundles seen with the surgical microscope on the intracranial arteries will be studied.